Just to get the terms correct: you would run a vnc-server on the host, (or in a linux vm guest) and use a client to connect to the vnc-server. Centos comes with a vnc server built in - you just have to enable it. And vnc is only needed to use the graphical desktop. It's not needed if you use command line administration. As far as headless operations - I use the power button to turn it on, and the shutdown command in a terminal window to shut it down. (after manually shutting down the vm guests) I suppose you can script the automatic shutdown of guests, but I haven't gotten around to that... Sorry, I don't know what krdc is. You use the network (ethernet) to connect.